The nature of written and oral peer feedback will be described as it occurred in seven writing courses, each with a different design of peer assessment. In all courses, peer feedback was focused on evaluation, which is one of the four feedback functions. Feedback on structure was hardly provided. Relating feedback to design features, we suggest that feedback is adequate when (1) peer assessment has a summative (on the basis of a writing product) as well as a formative character (during the writing process); (2) the assessment is performed in small feedback groups; (3) the written feedback is orally explained and discussed with the receiver.